U.S. patent number 9,482,403 [Application Number 14/667,789] was granted by the patent office on 2016-11-01 for automotive light and method of manufacturing.
This patent grant is currently assigned to Automotive Lighting Italia S.p.A. a Socio Unico. The grantee listed for this patent is Automotive Lighting Italia S.p.A. a Socio Unico. Invention is credited to Cristiano Boero, Alessandro Buzzurro, Domenico Ferigo, Fabio Leone, Nicola Schiccheri.
United States Patent |
9,482,403 |
Boero , et al. |
November 1, 2016 |
Automotive light and method of manufacturing
Abstract
A method of manufacturing an automotive light including the
steps of: providing at least one laser diode emitting a light beam
with a characteristic emission spectrum; providing a container body
delimited by a first perimetral profile; providing a molded
lenticular body delimited by a second perimetral profile and having
at least first and second overlapping integral layers with
different transmittance values in relation to the laser emission
spectrum; at least partially associating the perimetral profiles;
and at least partially welding at the perimetral profiles with the
laser, wherein the laser beam is routed towards the perimetral
profiles so as to reach the first perimetral profile after passing
through at least one of the layers of the lenticular body, and
wherein the container body acts as an absorbing member in relation
to the light beam and the lenticular body acts as a transmissive
member of the light beam.
Inventors: |
Boero; Cristiano (Torino,
IT), Ferigo; Domenico (Torino, IT),
Schiccheri; Nicola (Torino, IT), Leone; Fabio
(Torino, IT), Buzzurro; Alessandro (Torino,
IT) |
Applicant: |
Name |
City |
State |
Country |
Type |
Automotive Lighting Italia S.p.A. a Socio Unico |
Torino |
N/A |
IT |
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Assignee: |
Automotive Lighting Italia S.p.A. a
Socio Unico (Turin, IT)
|
Family
ID: |
51136633 |
Appl.
No.: |
14/667,789 |
Filed: |
March 25, 2015 |
Prior Publication Data
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Document
Identifier |
Publication Date |
|
US 20150276158 A1 |
Oct 1, 2015 |
|
Foreign Application Priority Data
|
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|
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Mar 28, 2014 [IT] |
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PD2014A0080 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F21S
41/29 (20180101); B29C 65/167 (20130101); B29C
65/1674 (20130101); B29C 66/131 (20130101); F21V
9/08 (20130101); F21S 43/27 (20180101); B29C
65/1687 (20130101); B60Q 1/0088 (20130101); B29C
66/301 (20130101); B29C 65/1635 (20130101); B29C
66/1142 (20130101); B29C 66/542 (20130101); B29C
66/723 (20130101); B29L 2011/00 (20130101); B29C
66/7332 (20130101); B29C 66/73322 (20130101); B29L
2031/30 (20130101); B29C 66/71 (20130101); B29C
66/73365 (20130101); B29K 2101/12 (20130101); F21Y
2115/10 (20160801); B29L 2031/747 (20130101); F21Y
2115/30 (20160801); B29C 65/1654 (20130101); B29C
66/71 (20130101); B29K 2033/12 (20130101); B29C
66/71 (20130101); B29K 2069/00 (20130101) |
Current International
Class: |
F21S
8/10 (20060101); B60Q 1/00 (20060101); B29C
65/00 (20060101); B29C 65/16 (20060101); F21V
9/08 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2003123506 |
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Apr 2003 |
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JP |
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2007109429 |
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Apr 2007 |
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JP |
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2011255628 |
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Dec 2011 |
|
JP |
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201228143 |
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Feb 2012 |
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JP |
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Other References
Jul. 31, 2014 European Search Report for Italian Patent Application
No. PD20140080. cited by applicant.
|
Primary Examiner: Truong; Bao Q
Attorney, Agent or Firm: Howard & Howard Attorneys
PLLC
Claims
What is claimed is:
1. A method of manufacturing an automotive light comprising the
steps of: providing at least one laser diode for emitting a light
beam or radiation having a characteristic emission spectrum;
providing a container body delimited by a first perimetral profile;
providing a molded lenticular body delimited by a second perimetral
profile and having at least a first and a second layer the
lenticular body including at least a first and a second layer, the
first layer and the second layer at least partially overlapping and
integral to each other, the first layer and the second layer having
different transmittance values in relation to the emission spectrum
of the laser diode; associating the first and second perimetral
profiles at least partially between each other; and laser welding
at least partially between the lenticular body and the container
body at said perimetral profiles, wherein the light beam emitted by
the laser diode is routed towards the perimetral profiles so as to
reach the first perimetral profile of the container body after
passing through at least one of the layers of the lenticular body
having different transmittance values in relation to the emission
spectrum of the laser diode, and wherein the container body acts as
an absorbing member in relation to the light beam and the
lenticular body acts as a transmissive member of the light
beam.
2. The method as set forth in claim 1, including the steps of:
providing at least one light source electrically connected to a
source of electric power, adapted to emit a light beam to propagate
outside the automotive light, and housed in a containment housing
delimited by the container body, wherein the lenticular body is
adapted to close the containment housing and is adapted to receive
the light beam generated from the light source and propagate the
light beam outside the light; providing the lenticular body in a
closing position of the containment housing of the container body
so as to associate the respective first and second perimetral
profiles with each other; wherein the first layer of the lenticular
body faces towards the outside of the automotive light, and the
second layer of the lenticular body faces towards the containment
housing, the layers having different transmittance values in
relation to the emission spectrum of the laser diode.
3. The method as set forth in claim 1, wherein the light radiation
emitted by the laser diode passes through both the first layer and
the second layer of the lenticular body before reaching the welding
area at an interface between the first and second perimetral
profiles.
4. The method as set forth in claim 1, wherein one of the layers of
the lenticular body is a layer in a polymer material having
transmittance values, in the emission spectrum of the laser diode,
greater than 90%.
5. The method as set forth in claim 1, wherein at least one of the
layers of the lenticular body is made from a substantially clear
material.
6. The method as set forth in claim 1, wherein at least one of the
layers is made from a polymer material having a predetermined
color, the layer having a transmittance sufficient to transmit the
light beam towards the perimetral profiles and not soften the
material hit by the light beam.
7. The method as set forth in claim 1, wherein the first layer and
the second layer of the lenticular body are made from the same
material.
8. The method as set forth in claim 1, wherein the material of the
first and/or the second layer of the lenticular body is a
resin.
9. The method as set forth in claim 1, wherein the layer of the
lenticular body having the greater transmittance value has a
greater thickness than the layer having the lower transmittance
value.
10. The method as set forth in claim 1, wherein the lenticular body
has an overall thickness of 4.5 mm, wherein 2 mm are for the layer
having the lower transmittance value and 2.5 mm are for the layer
having the greater transmittance value.
11. The method as set forth in claim 1, wherein said first and
second layers of the lenticular body are obtained via co-molding or
over-pressing technique.
12. The method as set forth in claim 1, wherein the lenticular body
is obtained with a multicolor injection molding technique using
equipment provided with a mold including a fixed platform having at
least two matrix half-molds, and a rotating platform having a punch
half-mold, capable of moving relative to the fixed platform, so as
to couple the punch half-mold to each matrix half-mold present on
the fixed platform.
13. The method as set forth in claim 1, wherein at the second
perimetral profile, the lenticular body includes a second contact
edge with the container body, the second contact edge following the
respective second perimetral profile and projecting from the latter
in the direction of the container body.
14. The method as set forth in claim 13, wherein the second contact
edge is integral to the second layer of the lenticular body.
15. The method as set forth in claim 14, wherein the second layer
of the lenticular body is the layer having greater
transmittance.
16. The method as set forth in claim 13, wherein the second contact
edge includes overlapping portions of the first and second
layers.
17. The method as set forth in claim 16, wherein the overlapping
portions include at least one protrusion of the first layer at
least partially penetrated into the second contact edge of the
second layer.
18. The method as set forth in claim 1, wherein the light radiation
emitted by the laser diode is directed at the perimetral profiles
according to a direction substantially perpendicular to the layers
of the lenticular body.
19. The method as set forth in claim 13, wherein the light
radiation emitted by the laser diode is directed so as to channel
into the second contact edge and to impact on the first perimetral
profile.
20. The method as set forth in claim 13, wherein at the second
perimetral profile, the lenticular body includes a folded portion
towards the container body, the folded portion being integral with
the lenticular body and defining the second contact edge with the
container body, the folded portion including an overlapping of the
first and second layers of the lenticular body.
21. The method as set forth in claim 20, wherein the light
radiation emitted by the laser diode is directed at the second
contact edge according to a direction substantially parallel to the
layers of the lenticular body.
22. The method as set forth in claim 20, wherein the light
radiation is directed so as to channel into the second contact
edge, along each of the layers of the lenticular body, and to
impact on the first perimetral profile.
23. The method as set forth in claim 13, wherein at the first
perimetral profile, the container body includes a first contact
edge with the container body, the first contact edge following the
respective first perimetral profile and projecting from the latter
in the direction of the lenticular body.
24. The method as set forth in claim 23, wherein the first
perimetral profile is at least partially counter-shaped relative to
the second perimetral profile; and wherein the first perimetral
profile has an abutment wall receiving in abutment the second
contact edge, the abutment wall having a thickness greater than or
equal to a corresponding support wall of the second contact
edge.
25. The method as set forth in claim 1, wherein the laser welding
step takes place via a simultaneous welding technique with one or
more optical fibers that emit respective light radiations
simultaneously on different predetermined portions of the
perimetral profiles.
26. The method as set forth in claim 1, wherein the laser welding
step takes place via a border welding technique with at least one
moving laser diode guided so as to route the light radiation along
the perimetral profiles.
27. An automotive light manufactured via the method as set forth in
claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application is based upon and claims priority to Italian
Patent Application No. PD2014A000080, filed on Mar. 28, 2014.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, generally, to automotive lights and,
more specifically, an automotive light and a method of
manufacturing an automotive light.
2. Description of Related Art
The term "automotive light" as used in the related art is known to
refer to either a rear automotive light or a front automotive light
(also known as a "headlight") for use as lighting and/or signaling
devices of a vehicle, which includes at least one external
automotive light having a lighting and/or signaling function
towards the outside of the vehicle (such as, for example: a
sidelight, an indicator light, a brake light, a rear fog light, a
reverse light, a dipped beam headlight, a main beam headlight,
etc.).
The automotive light generally includes a container body, a
lenticular body, and at least one light source. The lenticular body
is placed so as to close a mouth of the container body so as to
form a housing chamber. The light source is arranged inside the
housing chamber, which may be directed so as to emit light towards
the lenticular body when powered with electricity.
In manufacturing automotive lights, once the various components
have been assembled, there needs to be attachment and hermetic
sealing of the lenticular body to the container body. Typically,
sealing is effected by welding. It will be appreciated that welding
may also be utilized for other components of a more complex
automotive light, for example components arranged inside the
housing chamber.
There are a number of different welding solutions known in the
related art. From a mechanical point of view, the welds of the
prior art make it possible to realise joints which are reliable
over time both from the mechanical point of view, considering the
continuous mechanical and thermal stresses (vibrations, and
atmospheric conditions) to which an automotive light is continually
subjected; and from the sealing point of view, for example
preventing infiltration of water or dirt from the outside towards
the inside of the light.
Assembly techniques known in the related art can be expensive
because the welding processes of the lenticular bodies to the
container body are rather complex and, thus, slow. For example, it
is known of to use vibration welding techniques for the assembly of
automotive lights. Conventional laser welding applications in
automotive lights, with the techniques currently in use, are not
very efficient given that it is necessary to weld together complex
geometries such as those of automotive lights. Specifically, the
lenticular bodies and the container bodies of automotive lights are
made of polymeric materials with highly complex geometries and with
curved or straight coupling surfaces having inclinations highly
variable along the entire perimeter of the mutual coupling.
Moreover, it will be appreciated that laser welding of polymeric
bodies generally assumes localized supply of thermal energy capable
of locally melting polymeric bodies respectively having sufficient
transmittance and absorbance of electromagnetic radiation emitted
by a laser source (such as a laser diode). More specifically, light
energy of electromagnetic radiation emitted by the laser source is
transformed into heat during absorption in the absorbent polymer
body. The absorbent polymer body thus simultaneously melts locally
and conducts heat to the transmissive polymer body in a defined
welding area corresponding to an interface area between the bodies
in contact. The softened polymeric bodies can consequently
penetrate each other, connecting permanently once cooled.
In headlights, the polymeric bodies may include the lenticular body
and the container body of the automotive light, where the
lenticular body acts as a transmissive polymeric body and the
container body serves as an absorbent polymeric body. However, the
complex geometry of automotive lights or their components (such as
the container body and the lenticular body) are ill-adapted for use
with conventional laser welding techniques, which are in fact
optimised for applications on flat walls, simple geometries, and
relatively thin body thicknesses. Thus, laser welding techniques
are currently little used on automotive lights in that there is no
guarantee of satisfactory results and alternative welding
techniques are more cost/time competitive.
In addition, certain complexities of automotive lights further
discourages and makes current laser welding techniques
inconvenient. By way of example, a component of the automotive
light (such as the lenticular body) can be crossed by light emitted
by the light source so as to effect lighting of the automotive
light. The lenticular body may have a coloration so as ensure that
the color of the light emitted by the light source complies with
government-mandated regulations (for example, a stop light of the
automotive light may be realised with a substantially white light
source and a lenticular body tending to red). However, during the
laser welding process, a red colored lenticular body absorbs a lot
of light energy in comparison to a clear lenticular body to the
detriment of the light energy provided by the laser source, which
needs to be able to provide a predetermined light energy in the
welding area. The increased absorption due to the presence of a
colored lenticular body acting as the transmission element, which
filters the radiation emitted, requires the use of higher power
laser beams, which consequently results in high energy consumption
and increased welding costs.
Because of the foregoing considerations, laser welding techniques
are little used on conventional automotive lights since they are
too complex, expensive, and inconvenient to implement when compared
to alternative welding techniques, such as friction welding. Thus,
there remains a need in the art for a laser welding method of
polymeric bodies used in automotive lights able to reduce the power
of the laser source.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages in the related
art in an automotive light and a method of manufacturing the
automotive light. The method includes the steps of: providing at
least one laser diode emitting a light beam or radiation having a
characteristic emission spectrum; providing a container body
delimited by a first perimetral profile; providing a lenticular
body delimited by a second perimetral profile, wherein the
lenticular body is obtained via a molding technique such that the
lenticular body includes at least a first and a second layer at
least partially overlapping and integral to each other, with the
layers having different transmittance values in relation to the
emission spectrum of the laser diode; associating the respective
first and second perimetral profile of the container body and the
lenticular body at least partially between each other; and laser
welding at least partially between the lenticular body and the
container body at the perimetral profiles, wherein the light beam
emitted by the laser diode is routed towards the perimetral
profiles so as to reach the first perimetral profile of the
container body after passing through at least one of the layers of
the lenticular body having different transmittance values in
relation to the emission spectrum of the laser diode, and wherein
the container body acts as an absorbing member in relation to the
light beam and the lenticular body acts as a transmissive member of
the light beam.
In this way, the automotive light and method of the present
invention overcome the technical drawbacks in the related art which
otherwise make laser welding of automotive lights inconvenient and
expensive.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features, and advantages of the present invention
will be readily appreciated as the same becomes better understood
after reading the subsequent description taken in connection with
the accompanying drawings wherein:
FIG. 1 is an exploded perspective view of parts of an automotive
light.
FIG. 2 is an exploded perspective view of the automotive light and
equipment for welding the automotive light, according to one
embodiment of the present invention.
FIG. 3 is a perspective view of the automotive light and equipment
of FIG. 2 shown in an assembled configuration.
FIG. 4 is a further perspective view of the automotive light and
equipment of FIG. 2.
FIG. 5 is a partial sectional view of the automotive light and
equipment taken along line V-V of FIG. 4.
FIG. 6 is a sectional view of a welding step of an automotive light
and equipment according to one embodiment of the present
invention.
FIG. 7 is a sectional view of a welding step of an automotive light
and equipment according to another embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
The elements or parts of elements common to the embodiments
described below are indicated using the same reference numerals.
Referring now to the Figures, an automotive light is generally
indicated at 4. It will be appreciated that the automotive light 4
could be a rear automotive light or a front automotive light (also
known as a headlight). The automotive light includes at least one
outer vehicle light having a lighting and/or signaling function
(for example: a front, rear, or lateral sidelight; an indicator
light; a brake light; a rear fog light; a dipped beam headlight; a
main beam headlight; etc.).
The automotive light 4 includes a container body 8, usually of
polymeric material, which typically permits attachment of the
automotive light 4 to the vehicle. For the purposes of the present
invention, the container body 8 may be any shape and size, and may
even be an element inside the automotive light (for example: not
directly fixed to or associated with the bodywork or other
fastenings of the vehicle).
In one embodiment, the container body 8 delimits a containment
housing 12 which houses at least one light source 16, connected to
a source of electric power, and adapted to emit a light beam to
propagate outside the automotive light. For the purposes of the
present invention, the type of light source 16 used is irrelevant.
However, the light source 16 may advantageously be a light source
of light emitting diodes (LED).
The container body 8 is delimited by a first perimetral profile 20.
A lenticular body 24 in turn delimited by a second perimetral
profile 28 is joined to the container body 8. For the purposes of
the present invention, the lenticular body 24 may be either
external to the automotive light 4 so as to define at least one
outer wall of the automotive light directly subject to the
atmosphere; or the lenticular body may also be internal to the
automotive light 4, for example not directly subject to the
external atmosphere and in turn covered directly or indirectly by
one or more screens or covering panels.
In one embodiment, the lenticular body 24 may be adapted to close
the containment housing 12 and to transmit the light beam produced
by the light source 16 to the outside of the automotive light 4. To
this end, the lenticular body 24 may be made of at least partially
transparent or semi-transparent or translucent material, and may
also include one or more opaque portions so as to allow at least
partial crossing of the light beam produced by the light source
16.
The second perimetral profile 28 is counter-shaped relative to the
first perimetral profile 20 so as to be coupled with the latter
according to a shaped coupling, in the assembled configuration of
the automotive light 4. The assembly of the automotive light 4
includes the step of joining at least partially to each other the
respective first and second perimetral profiles 20, 28. For
example, the step is provided for of arranging the lenticular body
24 to close the containment housing 12 of the container body 8 so
as to join the respective first and second perimetral profiles 20,
28.
The method of manufacturing the automotive light provides for
joining the lenticular body and the container body to each other in
correspondence of the perimetral profiles 20, 28, via laser
welding. The laser welding process may be realized with different
techniques (for example: with simultaneous laser welding,
almost-simultaneous laser welding, border laser welding, mask laser
welding, radial laser welding, globe laser welding, etc.). However,
in the description that follows, specific reference will be made to
simultaneous laser welding for exemplary purposes and by way of
non-limiting example. In particular, at least a laser source is
provided which emits a laser beam or a light beam or an
electromagnetic radiation having a characteristic emission spectrum
(not shown, but generally known in the related art). Here, the term
"characteristic emission spectrum" refers to electromagnetic
radiation emitted substantially at a certain frequency or having a
certain wavelength. In one embodiment, the laser source is a laser
diode which emits a laser beam. In one embodiment, the laser source
may include: a CO.sub.2 laser, in which the laser beam is produced
by a gas mixture of CO.sub.2; or a YAG laser, in which the laser
beam is produced by a solid state crystal.
The laser source emits a light beam that can be sent directly to
the lenticular body 24. In one embodiment, the laser source is
associated with an optical fibre 32 inserted in a matrix/guide 33
which supports the optical fiber 32 and guides the light beam
emitted by the laser source. The welding advantageously takes place
after blocking the container body 8 in a respective attachment
block 35.
Advantageously, provided lenticular body 24 is manufactured via a
molding technique where the lenticular body 24 includes at least a
first and a second layer 36, 40 at least partially overlapping and
integral to each other. In one embodiment, the first layer 36 faces
outside of the automotive light 4, and the second layer 40 faces
towards the containment housing 12. Apart from the mutual
positioning of the layers, the layers 36, 40 advantageously have
different transmittance values in relation to the emission spectrum
of the laser source. More specifically, the layers 36, 40 have
different optical properties such that, in correspondence with the
characteristic emission spectrum of the laser source, they show
different transmittance values. Consequently, the light beam
emitted by the laser source will be transmitted or absorbed
differently by the two layers 36, 40.
In particular, the welding of the lenticular body 24 on the
container body 8 is a laser welding wherein the light beam emitted
by the laser diode is routed towards the perimetral profiles 20, 28
so as to reach the first perimetral profile 20 of the container
body 8 after passing through at least one of the layers 36, 40 of
the lenticular body 24 having different transmittance values in
relation to the emission spectrum.
During the welding step, the container body 8 acts as an absorbing
member in relation to the light beam emitted by the laser source
and the lenticular body 24 acts as a transmissive member of the
light beam.
In one embodiment, the light radiation emitted by the laser source
passes through both the first layer 36 and the second layer 40 of
the lenticular body 24 before reaching the welding area positioned
at an interface 44 between the first and second perimetral profiles
20, 28.
In one embodiment, one of the layers 36, 40 of the lenticular body
24 is a layer in a polymer material having transmittance values
greater than 90%, measured in the emission spectrum of the laser
source. For example, at least one of the layers 36, 40 of the
lenticular body 24 may be a layer made of a substantially clear
material.
In one embodiment, at least one of the layers 36, 40 is made of a
polymer material having a desired color, wherein the layer 36, 40
has a transmittance sufficient to not soften the material hit by
the light beam and to transmit the light beam towards the
perimetral profiles 20, 28 and towards the interface 44.
It is possible to make the first layer 36 and the second layer 40
of the lenticular body 24 with the same material. For example the
material of the first and/or second layer 36, 40 of the lenticular
body 24 is a resin such as PMMA, PC, and the like. In one
embodiment, the layer 36, 40 of the lenticular body 24 with a
greater transmittance value has a greater thickness than the layer
40, 36 with a lower transmittance value. In one embodiment, the
lenticular body 24 has an overall thickness of 4.5 mm, wherein 2 mm
are for the layer 36, 40 having the lower transmittance value and
2.5 mm are for the layer 40, 36 having the greater transmittance
value. Thus, there is improved energy efficiency since there is
lower power consumption for the same overall path to be traversed
by the light beam to reach the interface 44 (for example, thickness
of the lenticular body 24) and therefore higher transmission
efficiency is increased.
For the purposes of the present invention, the first and second
layers 36, 40 of the lenticular body 24 are obtained by a technique
of co-molding. For example, the lenticular body 24 is obtained with
a multicolor injection molding technique, wherein equipment is used
provided with a mold including a fixed platform having at least two
matrix half-molds, and a rotating platform having a punch half-mold
able to move relative to the fixed platform so as to couple the
punch half-mold with each matrix half-mold present on the fixed
platform.
Irrespective of the specific molding technique used, the lenticular
body 24 has, as shown, at least two layers 36, 40 integral with
each other and at least partially overlapping. The two or more
layers 36, 40 may advantageously be made of different colors:
typically, one of the layers is clear (or substantially
transparent) and the other is colored to filter the light emitted
by the light source so that the light beam produced in output from
the light has the desired color (for example, red for a side light
or stop light, orange for an indicator light, etc.). The coloration
(for example, doping) of the material to obtain a colored layer of
the lenticular body, modifies the transmittance for the same
spectrum of the incident beam: generally, the transmittance
increases in the absence of doping (for example, in the presence of
a clear layer), and decreases as the doping increases.
As noted above, because of the purposes of the functions of an
automotive light, assuming that the light sources commonly used
emit substantially white light beams (for example), the lenticular
body 24 needs to have one or more colored pieces so that the light
beam output has the desired color.
Conventional lenticular bodies welded with laser technology have
colored portions in a single piece: specifically, the lenticular
body is composed of a single colored layer and then doped in the
desired color, whish is inefficient at the moment of trying to
laser weld the lenticular body 24 to the container body 8.
Advantageously, according to one embodiment of the present
invention, the lenticular body instead has at least two layers
colored with different doping in order to at least partially
increase the overall transmittance of the lenticular body. This
effect can be obtained by applying a clear layer (with
transmittance greater than 90%) to a colored layer (for example:
red, with transmittance less than 90%), or overlapping two colored
layers so as to provide light output of the desired color and with
a total transmittance of the lenticular body that is better than
that of a corresponding single colored layer.
In one embodiment, at the second perimetral profile 28, the
lenticular body 24 includes a second contact edge 48 with the
container body 8, where the second contact edge 48 follows the
respective second perimetral profile 28 and projects therefrom in
the direction of the container body 8. This way, the light
radiation emitted by the laser source is directed so as to be
channelled in the second contact edge 48 and to impact on the first
perimetral profile 20 of the container body 8.
In one embodiment, the second contact edge 48 is integral with the
second layer 40 of the lenticular body 24. For example, the second
layer 40 of the lenticular body 24 is the layer having a higher
transmittance and also encompasses the second contact edge 48: this
way it further increases the path of the light beam inside the
layer having a higher transmittance
In one embodiment, the second contact edge 48 includes overlapping
portions of the first and second layers 36, 40 (see FIGS. 6-7). For
example, as shown in FIG. 6, the overlapping portions 36', 40'
include at least one protrusion 36' of the first layer 36 at least
partially penetrated into the second contact edge 48 of the second
layer 40.
With one possible welding technique, the light radiation emitted by
the laser source is directed according to a direction substantially
perpendicular to the layers 36, 40 of the lenticular body, at the
perimetral profiles 20, 28 (see FIG. 5).
In one embodiment, the lenticular body 24 at the second perimetral
profile 28 includes a folded portion 52 towards the container body
8. The folded portion 52 is integral with the lenticular body 24
and defines the second contact edge 48 with the container body 8,
and the folded portion 52 in turn includes an overlapping of the
first and second layers 36, 40 of the lenticular body 24 (see FIGS.
6-7). The light radiation emitted by the laser source is directed
at the second contact edge 48 according to a direction
substantially parallel to the layers 36, 40 of the lenticular body
24. In this case also, the light radiation is directed so as to
channel itself into the second contact edge 48, along each of the
layers 36, 40 of the lenticular body and to impact on the first
perimetral profile 20.
In one embodiment, at the first perimetral profile 20, the
container body 8 includes a first contact edge 56 in contact with
the container body 8. The first contact edge 56 follows the
respective first perimetral profile 20 and projects therefrom in
the direction of the lenticular body 24. The first perimetral
profile 20 is at least partially counter-shaped relative to the
second perimetral profile 28, and the first perimetral profile 20
has an abutment wall 60 which receives in abutment the second
contact edge 56. The abutment wall 60 forms the interface 44
between the lenticular body 24 and the container body 8.
Advantageously, the abutment wall 60 has a thickness greater than
or equal to a corresponding supporting wall 64 of the second
contact edge 48.
As mentioned above, the laser welding techniques for the
manufacturing method of the present invention may be of various
types. For example, according to a `simultaneous` welding
technique, the laser welding step may be performed by one or more
optical fibers which simultaneously emit respective light radiation
on separate predetermined portions of the perimetral profiles 20,
28. It is also possible to perform the laser welding step according
to a `border` welding technique with at least one mobile laser
source, with the relative optic fibers 32, which is guided so as to
direct the light radiation along the perimetral profiles 20,
28.
It will be appreciated that the manufacturing method according to
the invention makes it possible to overcome the disadvantages of
the prior art. Specifically, because of the method of the present
invention, it is possible to also apply the technique of laser
welding to automotive lights having any type of complex geometry,
such as geometry having curvatures and thicknesses highly variable
along the perimeter of the light.
The laser welding technique of the present invention is more
convenient than alternative welding techniques of the prior art in
the field of automotive lights, and affords advantages both in
terms of cost and time for the same quality of the welding joint.
In particular, because of the presence of at least two layers at
different transmittance values with respect to the emission
spectrum of the laser source, there is a reduction of consumption
(and therefore of costs) since a greater part of the light beam can
be transmitted to the welding interface between the lenticular body
and the container body. The light beam on the interface portion is
thus suitable to obtain a welded joint having excellent mechanical
qualities, without waste of luminous power. Further, irrespective
of the technique used to perform the laser welding step (for
example, the `border` or `simultaneous` type), the laser welding
step is quick and reliable, allowing a further reduction of
assembly costs for the same quality of the joint compared to the
prior art.
In addition, the utilization of a molded lenticular body with at
least two layers makes it possible to obtain perimeter profiles
and/or contact edges of the lenticular body having thicknesses
greater than those obtainable using conventional molding
techniques. Because of the increased thickness of the perimetral
profiles and relative contact edges of the lenticular body, it is
possible to channel and transmit to the container body a greater
part of the light beam to the benefit of a greater heating of the
weld joint which, thus, results in energy savings due to greater
energy efficiency. Moreover, because of the increased thickness of
the perimetral profiles and relative contact edges of the
lenticular body, it is also possible to channel a light beam having
a higher light output, for example, in order to weld in interface
zones (between the lenticular body and the container body)
relatively distant from the laser source emitter (for example, for
automotive lights having particular geometries and particularly
pronounced heights or thicknesses of the lenticular body). More
specifically, if the lenticular body is particularly advanced or
pronounced outwardly with respect to the interface surface, while
placing the laser source and the relative optical fibers at the
limit of contact with the outer surface of the lenticular body, the
light beam will have to cover a relatively long path before
reaching the interface surface. During the path, the light beam
will be at least partially absorbed by the lenticular body and
thus, in order to locally melt the container body (absorbent) at
the interface surface, a high power light beam would need to be
sent. This way, consumption would increase and there would be risk
producing unwanted melting or softening in different portions of
the lenticular body. In other cases, the presence of overly narrow
perimetral profiles and relative contact edges of the lenticular
body would lead to the non-melting of the plastic material at the
interface surface, making the welding impossible. Rather, because
of the realization of the lenticular body of at least two layers,
it is possible to create profiles and edges of adequate thickness,
obtaining an effective transmission of the light beam at elevated
distances or depths (for example, the distance between the outer
surface of the lenticular body and the interface surface between
the lenticular body and the container body), thus making laser
welding with any geometry of the automotive light possible and
efficient.
The invention has been described in an illustrative manner. It is
to be understood that the terminology which has been used is
intended to be in the nature of words of description rather than of
limitation. Many modifications and variations of the invention are
possible in light of the above teachings. Therefore, within the
scope of the appended claims, the invention may be practiced other
than as specifically described.
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